Top left is demon, bottom left is elf, middle is skyborne, and then we have demon again.  These are all very old, aside from the elven bridge which is probably a year younger than the rest.

The little demon house is of course totally incorrect, demons build everything with five sides when they can, and usually the doors are super long with two sections to accommodate the snow in the winter.  But I didn’t know that then.  I’ve got another picture of Masim’s restaurant where you can see it’s actually got a kind of pentagram shape to it, but it’s not nearly as “finished”.

It’s unlikely that we’ll be seeing any skyborne villages in the comic itself, but there’s a scribble of one at the bottom in the middle.  Same goes for the elves, but they do inhabit some of the area along the main storyline, so it’s slightly more likely.  Just like the skyborne tend to build on the sides of cliffs, elves tend to build on rivers and lakes.

I do have a few more scribbles related to architecture that include other variations, but these are the most common types, along with the typical human houses (but I didn’t draw any concepts for those).